vivoactive 4/4s SW 4.00 is now live

I'm using 3rd party watchface but it is good for battery and also garmins built in watchface witch also very good for battery and it is the same on this two watchfaces...

• Watchface setup made a big difference for me.  Garmin pre-installed watchfaces have been better for me than third party.  I use Garmin watch face with only time, date, sunrise/sunset and battery % displayed.  No seconds bar around the outside or HR displayed.  HR naturally fluctuates so much that I think it drains like displaying seconds does.  I flip to a widget to see that data. This basic setup would give you a baseline battery performance to judge other setups.

I'm still stuck with 3.90.... will this ever roll out to my region?

• I do. Generally 3.6d per charge is what I get with low use. I had a few days where I thought it was fixed but it reverted and is as bad as ever.

When using the pool swim activity, the pace fields are not giving the correct results on the watch. The pace value seems to be around 5-10% less then it should be. I did 1k swim in 21:20 and my pace in the data field was 2:00 but it should have been 2:08. The pace seems to be correct when viewed on the Garmin Connect app.

This battery issue: I had battery drain over 1% per day with hardly any usage. So I made factory reset, unninstalled every garmin stuff from phone and started again with clean setup. Everything oriented to battery life, only HR and Bluetooth running. I have third party watch face but very simple one with only one minute update. Brightness off. After all this i was around 0.3% consumption per hour. But only for two charging cycles. Now its getting worse every day. Now I am on 1.2% per hour, no activities, absolutely no change of settings, long-term average 1.9!

When I do some activity once per two days and for example sometimes wake watches for music control (only control, not playing) and notificatuons I am in reality on two days battery life at max

One of the reasons for buying was presented battery life, this is horrible! 

In my experiments with watch faces, I have yet to find a third party watch face that has performed as well as a pre-loaded Garmin watch face from a battery drain perspective.  This is true even if I am only displaying minimal stuff and nothing that updates frequently, like HR.

There must be something different behind.

I can take that third party watch face is not super-optimized and will be a little bit less efficient in terms of battery life. But I don't understand why I once have battery consumption 0.3% per hour and after two weeks with absolutely no change of settings 1.3%

It is not a watch face problem !!! 

Its true that third party watch face can consumpt more energy but it can be abaut 0.8%/h and another day witch the same watch face it can be 3%/h. 

In my opinion something inside the software drain battery or the battery power algorihm witch calculate battery percentage have some errors....

Today I have 0.5%/h witch third party watch face witch 2 (noGPS) activities. Yesterday I charged watch from PC by usb not from charger.

I agree that it is not exclusively a watch face problem.  My point is that watch face choice can definitely affect battery life.  I have had the watch for close to two months.  Aside from the first week when I was using a third party watch face and displaying things like HR, I have consistently been getting between 10 and 14 days per charge, with plenty of GPS use.  Without any GPS, I use about 5-6% per day.  With another third party watch face (with HR displayed), that was about 13-14% per day.  Some other third party watch faces are better than this, but none has been better than about 7-8% per day.

I suspect (but don't know) that the reason for my consistent battery performance is that I leave Bluetooth off except for syncing.  I use the watch for its fitness features, not so much its smart watch features.  It is definitely fair to say this watch should perform to spec as a smart watch, since it is marketed that way.  I just don't happen to use it much that way.

For the usb/pc charge vs. wall charge debate, I have always charged my watch with the supplied cord connected to a wall charger.